Concepts/Concept

Start with recovery

A map dataset has passed validation, processing, and publication when the process stops. Recovery needs precise answers: what completed, where the artifacts are, and which stage can resume. In-memory objects and terminal logs do not provide a stable contract.

Definition

A disk fact plane stores stage facts, execution state, and acceptance evidence in versioned files. Processes exchange paths and references instead of depending on unrecoverable shared memory.

In the Xuanxu case, metadata.json holds dataset and artifact facts, run-state.json holds stage progress and the resume point, and verify_report.json holds external acceptance evidence. Each fact has one authoritative writer. The console is a projection over these files.

Boundary

The implementation fits a single host or controlled shared storage. Multi-host, multi-tenant concurrent writes require transactional storage, locking, and isolation. The durable concept is an external, versioned, recoverable fact contract; disk is the carrier used in this case.

Provenance

• Initial case: Xuanxu Technology GIS publishing agent, contributed by Yuke Xiong.
• Lineage: file-based IPC, single source of truth, append-only state, and materialized projections.
• ADPS contribution: separate stage facts, runtime state, and acceptance evidence with one-writer ownership.
• Definition status: case-coined concept.